Various letter openers, either manually operable or electrically operable, have been available for assisting in opening letters. Such letter openers usually include a straight slot through which an envelope may slide. For a manually operated letter opener, a cutting blade is positioned to extend into the slot to cut open the envelope as the envelope passes through the slot. As to electrically operated letter openers, as the envelope enters or passes through the slot, a switch will be activated to actuate a rotary cutter to rotate to cut the envelope.
It is of course the case that different envelopes may have different thickness. A shortcoming associated with such conventional letter openers is that the depth to which the cutting blade or rotary cutter cuts into the envelope cannot be adjusted by the user to cater for the differences in the thickness of the envelopes.
In addition, it is also known that envelopes are usually pressed tightly during transport. This will increase the difficulty in cutting the envelopes, so that sometimes an envelope has to undergo the cutting process more than once, and sometimes the envelope may simply be torn open, and not cut open, thus damaging the envelope and possibly the content as well.
It is thus an object of the present invention to provide a letter opener in which the aforesaid shortcomings are mitigated, or at least to provide a useful alternative to the public.